<template>
  <div class="sub-filter" v-if="filterData && !filterLoading">
    <div class="item">
      <div class="head">品牌：</div>
      <div class="body">
        <a @click="changeBrand(brand.id)" :class="{ active: filterData.selectedBrand === brand.id }" href="javascript:;"
          v-for="brand in filterData.brands" :key="brand.id">{{ brand.name }}</a>
      </div>
    </div>
    <div class="item" v-for="p in filterData.saleProperties" :key="p.id">
      <div class="head">{{ p.name }}:</div>
      <div class="body">
        <a @click="changeAttr(p, attr.id)" :class="{ active: p.selectedProp === attr.id }" href="javascript:;"
          v-for="attr in p.properties" :key="attr.id">{{ attr.name }}</a>
      </div>
    </div>
  </div>
  <div v-else class="sub-filter">
    <XtxSkeleton class="item" width="800px" height="40px" />
    <XtxSkeleton class="item" width="800px" height="40px" />
    <XtxSkeleton class="item" width="600px" height="40px" />
    <XtxSkeleton class="item" width="600px" height="40px" />
    <XtxSkeleton class="item" width="600px" height="40px" />
  </div>
</template>
<script setup>
import { findSubCategoryFilter } from '@/api/category'
import { useRoute } from 'vue-router'
import { ref, watch } from 'vue'
const emit = defineEmits(['filter-change'])
// 1. 获取数据
// 2. 数据中需要全部选中，需要预览将来点击激活功能。默认选中全部
// 3. 完成渲染
const route = useRoute()
const filterData = ref(null)
const filterLoading = ref(false)
// 4. 分类发生变化的时候需要重新获取筛选数据，需要使用侦听器
watch(() => route.params.id, (newVal) => {
  // 当你从二级分类去顶级分类也会拿到ID，不能去加载数据因为它不是二级分类的ID
  if (newVal && route.path === ('/category/sub/' + newVal)) {
    filterLoading.value = true
    newVal && findSubCategoryFilter(route.params.id).then(({ result }) => {
      // 品牌属性全部
      result.selectedBrand = null
      result.brands.unshift({ id: null, name: '全部' })
      // 销售属性全部
      result.saleProperties.forEach(p => {
        p.selectedProp = null
        p.properties.unshift({ id: null, name: '全部' })
      })
      filterData.value = result
      filterLoading.value = false
    })
  }
}, { immediate: true })

// 获取筛选参数的函数
const getFilterParams = () => {
  const obj = { brandId: null, attrs: [] }
  // 品牌
  obj.brandId = filterData.value.selectedBrand
  // 销售属性
  filterData.value.saleProperties.forEach(item => {
    if (item.selectedProp) {
      const prop = item.properties.find(prop => prop.id === item.selectedProp)
      obj.attrs.push({ groupName: item.name, propertyName: prop.name })
    }
  })
  // 参考数据：{brandId:'',attrs:[{groupName:'',propertyName:''},...]}
  if (obj.attrs.length === 0) obj.attrs = null
  return obj
}

// 选择品牌
const changeBrand = (brandId) => {
  if (filterData.value.selectedBrand === brandId) return
  filterData.value.selectedBrand = brandId
  emit('filter-change', getFilterParams())
}
// 选中属性
const changeAttr = (p, attrId) => {
  if (p.selectedProp === attrId) return
  p.selectedProp = attrId
  emit('filter-change', getFilterParams())
}
</script>
<style scoped lang='less'>
.xtx-skeleton {
  padding: 10px 0;
}

// 筛选区
.sub-filter {
  background: #fff;
  padding: 25px;

  .item {
    display: flex;
    line-height: 40px;

    .head {
      width: 80px;
      color: #999;
    }

    .body {
      flex: 1;

      a {
        margin-right: 36px;
        transition: all .3s;
        display: inline-block;

        &.active,
        &:hover {
          color: @xtxColor;
        }
      }
    }
  }
}
</style>
